Automatic tab slitter for caser

ABSTRACT

Mechanism for severing tabs connected to adjacent edges of certain flaps of a shipping case to be packed with containers or the like in connection with casing operations, said tabs holding the upper flaps of a caser closely against the outer surfaces of the sides and ends of a case incident to being loaded. The caser includes mechanism to elevate the cases successively to loading mechanism and incident to such elevation, tab-severing means are positioned to engage the tabs to sever the same and thereby permit the flaps to be closed as a subsequent operation. The tabsevering mechanism includes units respectively movable diagonally toward and from opposite corners of a case where the tabs are located and include rotatable serrated cutters which are powerdriven. Fluid-operated means also move said cutter units laterally toward said corners of a case to position the same for severing the tabs.

United States Patent [72] lnvcntor William F. Roth Hanover, Pa. [2] Appl. No. 860,369 [22] Filed Sept. 23, I969 [45] Patented July 20, 197i Chisholm-Ryder Company of Pennsylvania [73] Assignec Hanover, Pa.

[54] AUTOMATIC TAB SLITTER FOR CASER 17 Claims, 6 Drawing Figs.

[52] US. Cl 53/l67, 53/250, 53/381 R, 83/488 [5]] lnt.Cl 1365b 5/08, B65b 43/26, B65b 61/00 [50] Field of Search 53/381,

[561 References Cited UNITED STATES PATENTS 2,464,099 3/ I949 Ross 53/208 3,340,676 9/1967 Arnett 53/382 X 3,387,522 6/1968 Standley 53/38lX Primary Examiner-Travis S. McGehee Assistant Examiner-Neil Abrams At!0rney-C. Hercus Just ABSTRACT: Mechanism for severing tabs connected to adjacent edges of certain flaps of a shipping case to be packed with containers or the like in connection with casing operations, said tabs holding the upper flaps of a caser closely against the outer surfaces of the sides and ends of a case incident to being loaded. The caser includes mechanism to elevate the cases successively to loading mechanism and incident to such elevation, tab-severing means are positioned to engage the tabs to sever the same and thereby permit the flaps to be closed as a subsequent operation. The tab-severing mechanism includes units respectively movable diagonally toward and from opposite comers of a case where the tabs are located and include rotatable serrated cutters which are power-driven. Fluid-operated means also move said cutter units laterally toward said corners of a case to position the same for severing the tabs.

PATENIEnJuLzolsn snwms INVENTO WILLIAM ROTH F'6RNEY PATENTEDJuL2019n 3,593,489

sum 2 OF 2 WILLIAM F ROTH T T ORNF y AUTOMATIC TAB SLITTIIR FOR CASER BACKGROUND OF THE INVENTION In casing operations in which shipping cases formed from corrugated board and otherwise are loaded or packed with containers or other items, a relatively recent innovation has been introduced wherein the blanks from which the cases are formed include locking tabs extending between adjacent ends of the flaps which ultimately become the upper flaps of a case when folded into cubical configuration and the bottom flaps have been folded into closed position for movement to a loading station in a casing machine commonly referred to as a caser. It is only necessary to provide two tabs or tab locks respectively in diagonally opposite corners of the case. The purpose of the tabs is to hold'the top flaps of the case closely adjacent the outer surfaces of the side and end walls thereof so as to be free of interference with various operations which the case may encounter during various operations leading to the loading or packing of the case with the items ultimately to be disposed therein.

While the provision of such locking tabs admirably suits the intended purpose until the case is packed, a problem is presented thereby in regard to the most expeditious and effective manner of severing said locking tabs so as subsequently to permit the upper flaps to be folded into closed position over the items packed into the case. Normally, the case packer is the last machine or unit of casing mechanism which is used prior to the case being closed and sealed, whereby cutting the tabs incident to or immediately after packing the case is necessary in order to effect such final closing and sealing of the case.

At present, such tabs are severed manually and thus constitutes a relatively expensive operation as distinguished from the use of automatic equipment to accomplish the same. Further, such severing must be effected with relative precision in that (l) the tab must preferably be completely severed, but (2)' no appreciable cutting of the corner of the case immediately adjacent the tab should occur. Further, cutting corrugated board usually requires precise cutting equipment which should be quite sharp or the cutting results in skinning and tearing the outer paper sheet of the board in an unsightly manner, in addition to frequently not effecting complete severance of such locking tabs.

SUMMARY OF THE INVENTION It is the principal object of the present invention to provide automatically operable mechanism for cutting or severing the locking tabs on cases of the type described above, such severing means being positioned adjacent the path of movement of cases in the immediate vicinity of the elevating means by which empty cases are raised toward a packer unit of a casing mechanism or machine, whereby the elevating movement of the cases is used to effect relative movement between the locking tabs of each case and the severing mechanism which simultaneously effects precise and adequate severance of both tabs on each case.

It is a further object of the invention to utilize poweroperated rotatable blades having serrated peripheries to effect such severing of the lockin g tabs.

It is a further object of the invention to provide means to move the power-operated tab-severing means laterally toward and from the corners of cases which embody the locking tabs, such movement being effected by fluid-operated means which preferably is in circuit with the case-elevating means of the caser which also is fluid operated.

It is another object of the invention to provide self-centering or aligning means on the tab-severing unit, whereby the severing knives are accurately positioned in vertical alignment with said tabs so as to sever the same when the case is elevated incident to being packed by the packing unit of the caser.

Detailsof the invention and of the foregoing objects, as well as other objects thereof, are set forth in the following specifcation and illustrated in the accompanying drawings'comprising a part thereof.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. I is a vertical elevation of the packing end of a casing machine as generally seen along the line I-I. of FIG. 2 and illustrating the tab-severing means provided in accordance with the present invention.

FIG. 2 is a horizontal plan view ofthe forward portion ofthe casing machine illustrated in FIG. I as seen on the line 2-2 of said figure.

FIG. 3 is a fragmentary side elevation showing the initial position of a case having tabs on the downwardly folded, upper flaps which are to be slit and also showing the position of a tab-slitting or severing unit relative to said initial position of said case.

FIG. 4 is an exemplary side elevation shown diagrammatically, of a case raised to packing position by elevating means in the casing machine and showing the upper flaps after the tabs have been slit.

FIG. 5 is a fragmentary top plan view, on a larger scale than in the preceding figures and illustrating details ofa tab-slitting unit embodying the principles of the present invention.

FIG. 6 is a fragmentary side elevation of the tab-slitting unit shown in FIG. 5, part of the supporting means being broken away for foreshorten the view.

DESCRIPTION OF THE PREFERRED EMBODIMENTS The casing mechanism or caser 10 illustrated in FIG. 1 is of a commercial type well known in the casing industry. It includes a rugged frame 12 having horizontal transverse members 14 near the bottom thereof which extend between the lower ends of the frame members 12 that terminate in floor pads 16. The horizontal frame members 14 support a conveyor frame [8 which includes vertically disposed side plates 20 which are suitably affixed to the frame members 12 and 14. Connected to each of the side plates 20 is a pair of longitudinally spaced vertically adjustable supports 22 which are shown in FIG. I. The upper ends thereof support horizontal members 24.

Aligning and advancing means 26 are shown in the upper portion of FIG. 1 which are of conventional nature and provide parallel patch along which exemplary containers 28 are advanced in parallel rows. Such aligning and advancing means 26 comprise part of case-packing mechanism which also includes vertical guiding units 30 each comprising parallel sets of spring fingers shown in dotted lines in FIG. 1. There is a set of such fingers for each container 28 for purposes of cushioning downward movement and insuring accurate guiding of the containers into the compartments formed by corrugated board dividers which are disposed in the case 32, for example, in order to separate each of the containers 28 from contacting each other when the same are lowered into the case. Such dividers are of well-known construction widely used in the casing industry, especially in regard to packaging glass containers within shipping cases.

The caser 10 also is provided with several types of conveyor means mounted within conveyor frame 18. One of these types comprises an endless friction belt 34 which extends around supporting and driving drums 36 and 38 shown in FIG. I. The other type comprises a pair of parallel endless flat top chains 40 which, as shown in FIG. 2, are spaced apart to accommodate the friction belt 34 thcrebetwcen as well as the elevating plate 42 by which the cases 32 are elevated from the lower position shown in exemplary manner in FIG. 3 to the packing position shown in FIGS. I and 4.

From FIG. 2, it also will be seen that the upper course of the friction belt 34 extends from the entrance end of the caser 10, which is at the left-hand end of the illustrations thereof shown in FIGS. 1 and 2, to the leading edge of the elevating plate 42. It is essential in casers of this type that the empty cartons be moved to the elevating plate 42 by the friction belt 34 due to the light weight thereof in empty condition. While engaged by the friction belt 34, the bottom of the case 32 is only lightly engaged by the flat top conveyor chains 40 but after the case has been elevated as shown in FIG. 1 to receive a full complement of the containers 28 and be packed therewith, the case is then much heavier. Upon the elevating plate 42 being lowered, opposite side portions of the case respectively engage the conveyor chains 40 for movement thereof to the discharge end of the caser which is adjacent the right-hand end thereof shown in FIGS. 1 and 2.

The principal novel feature of the present invention comprises means to sever the tabs 44 whichv connect adjacent ends of the upper flaps 46 and 48, which flaps respectively are folded downwardly from the upper edges of the open top of case 32, as shown in FIG. 3. As explained hereinabove, when the blank for the case 32 is formed, it is stamped from a sheet of corrugated board of the like and is suitably creased and incised so that when folded into flat condition, both of each of the side and end panels are foldably connected and are disposed in flat condition. In this condition, the bottom flaps, which are not shown in the figures, extending beyond said side and end walls of the flattened case, but within the planes thereof, while the upper flaps 46 and 48 are folded flatly against the outer surfaces of the upper portions of said side and end panels ofthe flattened case. I

The foregoing arrangement is such that when the case is erected from flattened condition, into expanded, cubical condition and the bottom flaps are folded into engagement with each other, the tabs 44, which preferably are located only at diagonally opposite corners of the case, will retain each pair of the upper flaps 46 and 48 in downwardly folded condition against the sides and ends of the case 32 in order that the upper flaps will not interfere with any of the casing arrange ments and operations which occur rior to the opened case being packed when the case is elevated to the packing mechanism as illustrated in FIG. I.

When a full complement of containers or other objects are packed into the case 32, there is no longer any need for the tabs 44 to remain intact and thereby hold the upper flaps in downwardly folded condition. Usually, the next operation is to fold the upper flaps into folded condition in which they overlie the contents of the case and the upper flaps usually are then sealed, thereby concluding the packing operation.

In accordance with the principles of the invention, it has been found appropriate, as well as simple and effective, to provide tab-severing mechanism in the form of units 50 which may readily be installed either in casers which already have been placed in service or upon new casers at the time of manufacturing the same. The tab-severing units 50 preferably comprise postlike support means 52 which are best illustrated in FIGS. 1 and 6, the latter figure showing the support means in terrupted to foreshorten the illustration thereof. Said support means conveniently may comprise an adequate length of suitable diameter ofindustrial tubing or pipe.

The lower end of support means 52 preferably is threaded into a suitable flanged base 54, best shown in FIG. 6, which flange is provided with a tapped hole into which a locking bolt 56 may be threaded after extending through a suitable hole in the lower horizontal flange of the horizontal members 24 at suitable locations therein at opposite sides of the caser. The upper end of support means 52 may be threaded into a threaded boss 58, shown in detail in FIG. 6, which may comprise a commercial nut of suitable size, the upper face of which preferably is welded to a baseplatc 60 with which each unit 50 is provided.

The baseplate 60 is provided with a short post 62 which extends upwardly from one end thereof for purposes of having one end of'a fluid-operated cylinder connected thereto by means which preferably permit a limited amount of pivotal movement of said cylinder relative to the axis of post 62. This is readily accomplished by means of a bolt 66 which extends through an ear projecting axially from the cylinder 64 and is threaded into the post 62.

A piston, not shown, is movable in opposite directions relative to cylinder 64 by fluid introduced respectively into op' posite ends thereof by conduit means of conventional nature which are not shown in dctailbut it will be understood that the same are of the type normally employed for such purposes. Said piston which is reciprocable within cylinder 64 is connected to a piston rod 68, the outer end of which is fixed to a guide block 70 which is provided with a right-angled notch 72 in the outer end thereof, as is best shown in FIG. 5. Thc'walls defining said notch respectively are engagcablc with outer surfaces of one corner of the case 32, as shown in FIG. 5, when the cylinder and piston unit 64, 68 project guide block 70 toward said corner of the case, as can be seen from FIG. 2.

Fastened to one side of guide block 70 is an angled bracket 74, which has a long leg fastened to one side of power means comprising anelectric motor 76, and a short leg, shown best in FIG. 5, fastened to said guide block 70 by a bolt 78. The shaft of the motor 76 extends through a bearing 80 on block 70 and intersects a slot 82 in said guide block 70 which bisects the angular notch 72 and extends inwardly therefrom for purposes of receiving tab-severing means preferably comprising a circular blade 84. Said blade preferably has a notched periphery to provide saw-type teeth which insure positive severance of said tabs. Blade 84 is at least partially illustrated in FIG. 6. For purposes of facilitating the connection of the blade 84 to the shaft of motor 76, the guide block 70 is provided with an access hole 86 of suitable size which extends inward from the face of the block which is parallel to and opposite that which supports the bearing 80, said opening being best shown in FIG. 6.

From the foregoing, it will therefore be seen that the guide block 70 is fixed to the outer end of piston rod 68 so as to be movable with cylinder 64, at least through a very limited angular movement about the axis of pivot bolt 66. In view of the fact that motor 76 is rigidly connected to the guide block 70 by brackets 74, it also will move with the guide block and cylinder through such limited angular movement, thereby carrying thc'circular blade 84 therewith.

Such pivotal movement is guided by an upper guide plate 88 which extends across a pair of spaced pillars 90, the lower ends of which are fixed to the base plate 60 of each of the tabsevering units 50. Securing bolts 92 extend through suitable holes adjacent opposite ends of the upper guide plate 88 and are threaded into the upper ends of the pillars 90. In accordance with the preferred design of the units 50, the width of the guide block 70 is such that there is a limited amount of space between the opposite sides thereof and the pillars when the guide block is disposed intcrmediately between them.

From FIG. 2, it will be seen that the caser 10 is provided with a pair of the tab-severing units 50 which respectively are adjacent opposite sides thereof and respectively are pivotally supported upon the upper ends of the supports 52 which are fastened to the horizontal members 24 of the main frame of the caser. Due to the vertical adjustability afforded by the vertical supports 22, as described hereinabove, it is possible to adjust the effective operating range of the periphery of the circular blades 84 of each unit to function at a desired elevation above the conveyors 34 and 40. Thus, upon the elevation of a case 32 by the elevating plate 42, which is effected by means of fluid-operated cylinder 94, and the movement of guide blocks 70 of each of the severing units 50 and the circular blades 84 therein laterally to the inwardly extended positions thereof by the power means comprising the fluid-operated cylinders 64 and the pistons therein, the diagonally opposite tabs 44 of case 32 will be moved vertically and simultaneously into contact with and past the peripheries of the circular blades 84 and be severed thereby.

To effect desired severing of the tabs without appreciably contacting the exterior surfaces of the corners of the case 32 per se which underlie each tab 44, it is essential thatwhe'n the circular blades 84 are moved into operative position to sever the tabs, such movement must be stopped precisely. This is accomplished by means of an adjusting nut 96 which is threaded onto each piston rod 68 to maintain the guide block 70 of each unit 50- in a precise and accurately determined position longitudinally upon each piston rod 68 after the same has been threadably adjusted to a desired position thereon. Any other equivalent adjusting means may be employed in lieu of said adjusting means or lock nut 96, ifd'esired.

In operation of the device, an empty case 32, arranged in the condition shown in FIG. 3, is delivered to the friction belt conveyor 34 in empty condition with the top open due to the side and end flaps 46 and 48 being maintained in downwardly folded position by the tabs 44 as described above. The fric' tional engagement between the conveyor 34 and the bottom of the case 32 is adequate to fully advance the empty case onto the elevating plate 42. Stop mechanism 98 is provided with a contact plate 100 which is engaged by the leading end of the empty case 32 when it is fully positioned upon plate 42. Said contact plate is connected to a. microswitch or any other equivalent means which is energized when light pressure is exerted against the same.

The aforementioned mechanism. is in circuit with control me,ans,.not shown, for fluid which isdclivered through suitable conventional-type conduits, not shown, simultaneously to both of the cylinders 64 as well as cylinder 94. Such action projects both tab-severing mechanisms comprising circular blades 84 simultaneously into position to engage the tabs 44 andisever the same incident tothe elevating plate 42 raising thecase, asshown in FIG. 1, to the packing position to receive a full complement of containers 28 or equivalent items which are to be packed into the case. As explained above, maintainingthc tabs 44' intact after this occurs-is needless.

Uponthc case 32' being packed with a complement of items itis to receive, suitable and conventional additional control means, notshown, are actuated to reverse the delivery of fluid under pressure to the'opposite ends of the cylinder 64 and 94 so as simultaneously to retract the tab-severing blades 84 and also lower the packed case 32' onto the endless conveyor chains 40 when the elevating plate 42 is retracted to its lower position. it is to be understood that both of the cylinders 64 and/or 94 may, if desired, be of the type which are energizedin'on'e' direction only by fluid under pressure and retraction may be effected by appropriate spring means of well-known type, not shown.

By the time the packed case 32 has been lowered onto the conveyor chains 40, the guide blocks 70 and other elements of the severing means associated therewith will have been retracted to idle position as shown in FIG 2, thereby offering no obstruction to the passage of the packed case 32 toward the discharge end of the caser 10, either due to the lateral arrangement of the tab-severing units or the vertical position thereof, or both.

It also will be seen that due to the limited amount of selfcentering, pivotal movement which is permitted to guide blocks 70 of each unit 50 and the elements connected thereto and movable therewith, automatic centering and consequent accurate positioning of the tab-severing blades 84 relative to said. tabs is assured. This is due to the guiding function afforded by the walls of angular notch 40 in the forward end of each of the guide blocks 70, which walls extend vertically and in parallel relationship respectively to the connected side and end panels which form one corner of the case 32. Accordingly, any limited variations in the positions of successive cases upon the elevating plate 42 or'of slight variations in the shapes and sizes of cases 32 will be of no consequence as far as the effective severance of the tabs 44- is concerned, which severance also will occur simultaneously relative to all tabs on the case.

In the preferred operation of the device, particularly if the power'means for thecircular blades 84 comprise the electric motors 76, said motors are arranged to operate continuously whilethe machine is in operation, rather than effect periodic operation thereof which would occur, for example, only while the cases are being elevated past the periphery of the blades 84'. Bysuch arrangement, costly additional control mechanism is unnecessary and the amount of power required to operate the motor 76 continuously is negligible, especially in view of the limited amount of power required to effectively sever the tabs 44. Further, if desired, hydraulic motors or other equivalent power means may be used in lieu of the electric motor 76, within the purview of the present invention.

While the invention has been illustrated and described in its several preferred embodiments, it is to be understood that the same is not to be limited to the details herein illustrated and described since the same may be carried out in other ways falling within the scope of the invention as illustrated and described. I

I claim:

I. A case filling and handling machine operable to fill shipping cases with containers and having conveyor means to move empty cases to filling mechanism and elevating means operable to raise cases from said conveyor means to said filling mechanism, said cases having the upper end maintained open by means of the upper flaps being locked against the sides of each case by tabs connected between the adjacent ends of certain flaps, in combination with cutter means, and means supporting said cutter means adjacent and a fixed distance above said conveyor means and said elevating means and in position to engage and cut the tabs on a case so as to completely sever the same when a case is raised by said elcvating means to said filling mechanism.

2. The machine according to claim 1 further including means to move said tab-severing means laterally toward the corners of cases when said cases reach said elevating means and are to be raised, thereby to bring said tabs and severing means into engagement with each other.

3. The machine according to claim 2 in which said severing means further include self-centering means operable to guide each severingmeans toward a comer of each case.

4. The machine according to claim 3 in which said self-centering means comprise guide blocks having angularly related faces thereon respectively engageable with surfaces of adjacent downwardly extending upper flaps of a case and operable to effect disposition of said severing means in precise vertical alignment with the tabs connected to said flaps.

5. The machine according to claim 2 in which said means to move said severing means laterally toward the comers of a case comprise fluid-operated means.

6. The machine according to claim Sin which said machine includes fluid-operated means connected to said elevating mechanism to raise and lower a case relative to said packing mechanism, and means connecting said fluid-operated means for said elevating mechanism and the fluid-operated means for said severing means to a source of fluid under pressure, and control means for said fluid under pressure operable to effect simultaneous actuation of all of said fluid-operated means.

7. The machine according to claim 1 in which said severing means comprise rotatably supported cutters and said severing means also including power-actuated means connected to said cutters to operate the same.

8'. The machine according to claim 7 in which said movable cutters are circular and are supported for rotation, the periphery of said cutters being serrated.

9. The machine according to claim 7 in which each of said severing means is part of a unit which includes said poweroperated means and said cutter, and means supporting said unit for'lateral movement toward and from certain corners of a case when said case is disposed upon said elevating mechanism and is to be raised toward said severing means.

10; Mechanism to sever the tabs of cases for containers which extend between adjacent edges of certain upper flaps of a case to maintain the same against the sides of the case at least until it reaches elevating means and filling means in a machine for purposes of filling such cases, said severing mechanism comprising in combination, support means adapted to be aligned with said filling means and connected to such a machine adjacent the path of movement for cases to be moved to said filling means, and severing means comprising a cutter supported by said support means and adapted to be positioned by said support means in vertical alignment with the tabs on a case when said tabs are moved vertically past said cutter incident to elevating said case to said filling means.

11. The tab-severing mechanism according to claim 10 further including guide means upon said support means, and additionally including means to move said severing means relative to said support means in opposite lateral directions toward and from the tabs of a case which are to be severed thereby.

12. The tab-severing mechanism according to claim 11 further including power means connected to said severing means and operable to effect said movement thereof in opposite lateral directions.

13 The tab-severing mechanism according to claim 12 in which said power means comprise fluid-operated cylinder and piston means connectable to a source offluid under pressure.

14. The tab-severing mechanism according to claim 10 in which said severing blade comprises a power-operated rotatable blade.

15. The tab-severing mechanism according to claim 14 in which said rotatable blade is circular and the periphery thereof is serrated.

16. The tab-severing mechanism according to claim 14 in which said power means for rotating said blade comprises a unit, and means supporting said unit for lateral movement relative to said support means to dispose said severing means of said unit in position to engage tabs of a case to be severed thereby. t

17. The tab-severing mechanism according to claim 16 in which said unit also includes fluid-operated means connected to said unit and operable to effect such lateral movement thereof. 

1. A case filling and handling machine operable to fill shipping cases with containers and having conveyor means to move empty cases to filling mechanism and elevating means operable to raise cases from said conveyor means to said filling mechanism, said cases having the upper end maintained open by means of the upper flaps being locked against the sides of each case by tabs connected between the adjacent ends of certain flaps, in combination with cutter means, and means supporting said cutter means adjacent and a fixed distance above said conveyor means and said elevating means and in position to engage and cut the tabs on a case so as to completely sever the same when a case is raised by said elevating means to said filling mechanism.
 2. The machine according to claim 1 further including means to move said tab-severing means laterally toward the corners of cases when said cases reach said elevating means and are to be raised, thereby to bring said tabs and severing means into engagement with each other.
 3. The machine according to claim 2 in which said severing means further include self-centering means operable to guide each severing means toward a corner of each case.
 4. THe machine according to claim 3 in which said self-centering means comprise guide blocks having angularly related faces thereon respectively engageable with surfaces of adjacent downwardly extending upper flaps of a case and operable to effect disposition of said severing means in precise vertical alignment with the tabs connected to said flaps.
 5. The machine according to claim 2 in which said means to move said severing means laterally toward the corners of a case comprise fluid-operated means.
 6. The machine according to claim 5 in which said machine includes fluid-operated means connected to said elevating mechanism to raise and lower a case relative to said packing mechanism, and means connecting said fluid-operated means for said elevating mechanism and the fluid-operated means for said severing means to a source of fluid under pressure, and control means for said fluid under pressure operable to effect simultaneous actuation of all of said fluid-operated means.
 7. The machine according to claim 1 in which said severing means comprise rotatably supported cutters and said severing means also including power-actuated means connected to said cutters to operate the same.
 8. The machine according to claim 7 in which said movable cutters are circular and are supported for rotation, the periphery of said cutters being serrated.
 9. The machine according to claim 7 in which each of said severing means is part of a unit which includes said power-operated means and said cutter, and means supporting said unit for lateral movement toward and from certain corners of a case when said case is disposed upon said elevating mechanism and is to be raised toward said severing means.
 10. Mechanism to sever the tabs of cases for containers which extend between adjacent edges of certain upper flaps of a case to maintain the same against the sides of the case at least until it reaches elevating means and filling means in a machine for purposes of filling such cases, said severing mechanism comprising in combination, support means adapted to be aligned with said filling means and connected to such a machine adjacent the path of movement for cases to be moved to said filling means, and severing means comprising a cutter supported by said support means and adapted to be positioned by said support means in vertical alignment with the tabs on a case when said tabs are moved vertically past said cutter incident to elevating said case to said filling means.
 11. The tab-severing mechanism according to claim 10 further including guide means upon said support means, and additionally including means to move said severing means relative to said support means in opposite lateral directions toward and from the tabs of a case which are to be severed thereby.
 12. The tab-severing mechanism according to claim 11 further including power means connected to said severing means and operable to effect said movement thereof in opposite lateral directions.
 13. The tab-severing mechanism according to claim 12 in which said power means comprise fluid-operated cylinder and piston means connectable to a source of fluid under pressure.
 14. The tab-severing mechanism according to claim 10 in which said severing blade comprises a power-operated rotatable blade.
 15. The tab-severing mechanism according to claim 14 in which said rotatable blade is circular and the periphery thereof is serrated.
 16. The tab-severing mechanism according to claim 14 in which said power means for rotating said blade comprises a unit, and means supporting said unit for lateral movement relative to said support means to dispose said severing means of said unit in position to engage tabs of a case to be severed thereby.
 17. The tab-severing mechanism according to claim 16 in which said unit also includes fluid-operated means connected to said unit and operable to effect such lateral movement thereof. 